998 resultados para Técnicas de cultura celular


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O objetivo deste estudo foi avaliar a possibilidade de agrupar talhões de cana-de-açúcar colhida mecanicamente e sem queima prévia da palha na região de Ribeirão Preto-SP, de acordo com o potencial de infestação de plantas daninhas, por meio de análise de agrupamento por método hierárquico e outras técnicas de análise multivariada, utilizando como variável o índice de infestação relativa atribuído por avaliações visuais, em duas etapas. A primeira contemplou 20 talhões de cana-planta com ciclo de 18 meses; essas áreas foram utilizadas para comparação de dois métodos de estimativa da composição específica da flora daninha: análise fitossociológica e por meio da porcentagem visual de cobertura geral (CG) e específica (CE). A segunda etapa consistiu no levantamento da composição específica da comunidade de plantas daninhas em 189 talhões, em áreas de cana-soca colhidas durante a safra de 2008, incluindo nesses talhões apenas CG e CE. Com as informações sobre os levantamentos da comunidade infestante foi construído um banco de dados, posteriormente submetido a análises exploratórias por técnicas de estatística multivariada. Para as principais espécies dentro dos talhões, que foram DIGNU, ARACH, IPOHF, MRRCI e IPOQU, seguidas de CYPRO, ELEIN e EPHHS, foram verificados 75% de coincidências de resultados entre os dois métodos de avaliação. Também notou-se que as avaliações visuais de porcentagem de cobertura das espécies podem substituir, para fins de praticidade, agilidade e aplicabilidade, as avaliações fitossociológicas, uma vez que proporcionaram boa capacidade de detecção das principais plantas daninhas dentro de cada talhão. As técnicas de estatística multivariada demonstraram que os talhões podem ser agrupados de acordo com semelhanças na intensidade da infestação e na composição específica.

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O estudo da distribuição espacial da lagarta-do-cartucho, Spodoptera frugiperda (J.E. Smith), na cultura do milho é fundamental para garantir a utilização de estratégias de controle, otimização de técnicas de amostragem, determinação de danos econômicos e incorporação da dinâmica espacial dentro do modelo populacional. O experimento foi conduzido em três campos contendo 100 parcelas cada, sendo amostradas 10 plantas ao acaso por parcela, num total de 1000 plantas por campo em cinco datas de amostragem. Foram contados o número de lagartas pequenas (menor que 10 mm) e grandes (maior que 10 mm) por planta. As lagartas pequenas apresentaram um ajuste muito bom à distribuição binomial negativa e não à Poisson, indicando que esta categoria larval encontra-se agregada no campo. Os números de lagartas grandes por planta ajustaram-se razoavelmente à distribuição binomial negativa, com algumas datas ajustando-se à distribuição de Poisson. Portanto, as lagartas pequenas (alta densidade populacional) têm distribuição agregada no campo, enquanto que as lagartas grandes (baixa densidade populacional) podem ser mais dispersas no campo, tendendo à aleatoriedade.

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Foram conduzidos dois experimentos de campo em área experimental do Departamento de Nutrição Animal e Pastagens da Faculdade de Ciências Agrárias e Veterinárias (UNESP), Campus de Jaboticabal, com o objetivo de observar resíduos do herbicida imazethapyr na forragem da alfafa e analisar a interferência de plantas daninhas monocotiledôneas e dicotiledôneas. No primeiro experimento, o herbicida foi aplicado nas doses de 0,5 e 1,0 l do p.c./ha, nos estádios de desenvolvimento: início de brotação das gemas basais, estádio vegetativo, ou seja, antes da cobertura total do solo e início do florescimento da alfafa. Foi observado que o herbicida não deixou resíduo nas plantas da alfafa, podendo estas serem consumidas pelos animais, logo após seu tratamento. No segundo experimento, foi estabelecido com base no manejo de cortes da área experimental e na presença de plantas daninhas, quatro tratamentos: 1)corte no verão de 1996, sem a presença de invasoras, 2)corte no inverno de 1996, sem a presença de invasoras, 3)corte no verão de 1997, com predominância de espécies monocotiledôneas, 4)corte no verão de 1997, com predominância de espécies dicotiledôneas. A presença de plantas daninhas reduziu a produção de matéria seca da alfafa. Quanto aos valores de parede celular, observou menores de Hem (5,7) e Lig (5,1) e maior de PB (26,1%) nas plantas colhidas no inverno, devido à maior proporção de folhas.

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This research argues about the mathematical knowledge built in the tradition of the cassava flour production, seeking to analyse these mathematical knowledge in the perspective of the categories of time and measure, built and practiced in the flour production, located in Serra do Navio and Calçoene, in Amapá - Brazil. The following work discuss the identification and the description of the mathematics during the production activities of the flour, where is presented elements related to generation and transmission of the traditional knowledge, which is the basis for maintenance of the tradition of the flour, characterizing the research as an Ethnomathematic study. The methodological procedures highlight ethnographical techniques and elements that characterize the participating observation. The results obtained showed us that the flour workers articulate some length, area and volume measure due to own and traditionally acquired systems, which is apprehended and countersigned by other kind of culturally established system; thus they relativism the measures systems and the official calendars. And it lifts as one of the main proposal that the academic mathematics and the tradition establish knowledge make conjunction of the both knowledge, that is important for a possible reflection and application in the construction of a pedagogical practice in mathematical education, trying to establish points of socio-economic and cultural mark

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As técnicas de aplicação localizada e em taxas variadas de insumos agrícolas com auxílio da geoestatística têm sido umas das áreas de concentração de esforços recentes em pesquisas e desenvolvimento ligado à agricultura de precisão. Portanto, o trabalho teve como objetivo avaliar a necessidade de aplicação de calcário e fósforo com base no comportamento espacial de atributos químicos do solo. Foram feitas amostragens do solo a intervalos regulares de 50 m, em uma área de 42 ha, na profundidade de 0,0-0,2 m para determinação do pH, Ca, Mg, P, V% e cálculo da necessidade de calagem e superfosfato triplo. Os dados foram submetidos às análises da estatística descritiva, geoestatística e interpolação por krigagem. O uso da técnica de geoestatística possibilitou uma precisa descrição dos atributos do solo o que permitiu a definição de zonas de manejo, indicando os locais de ocorrência de déficit e excesso. A variabilidade espacial dos atributos químicos do solo, possibilita a recomendação de doses de calcário e fósforo com taxas variadas, proporcionando economia e maior eficiência na aplicação.

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The objective of this work is to draw attention to the importance of use of techniques of loss prevention in small retail organization, analyzing and creating a classification model related to the use of these in companies. This work identifies the fragilities and virtues of companies and classifies them relating the use of techniques of loss prevention. The used methodology is based in a revision of the available literature on measurements and techniques of loss prevention, analyzing the processes that techniques needed to be adopted to reduce losses, approaching the "pillars" of loss prevention, the cycle life of products in retail and cycles of continues improvement in business. Based on the objectives of this work and on the light of researched techniques, was defined the case study, developed from a questionnaire application and the researcher's observation on a net of 16 small supermarkets. From those studies a model of classification of companies was created. The practical implications of this work are useful to point mistakes in retail administration that can become losses, reducing the profitability of companies or even making them impracticable. The academic contribution of this study is a proposal of an unpublished model of classification for small supermarkets based on the use of techniques of loss prevention. As a result of the research, 14 companies were classified as Companies with Minimum Use of Loss Prevention Techniques - CMULPT, and 02 companies were classified as Companies with Deficient Use of Loss Prevention Techniques - CDULPT. The result of the research concludes that on average the group was classified as being Companies with Minimum Use of Techniques of Prevention of Losses EUMTPP, and that the companies should adopt a program of loss prevention focusing in the identification and quantification of losses and in a implantation of a culture of loss prevention

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The development of wireless telecommunication in the last years has been great. It has been taking academics to conceive new ideas and techniques. Their aims are to increase the capacity and the quality of the system s services. Cells that are smaller every time, frequencies that are every time higher and environments that get more and more complex, all those facts deserve more accurate models the propagation prediction techniques are inserted in this context and results with a merger of error that is compatible with the next generations of communication systems. The objective of this Work is to present results of a propagation measurement campaign, aiming at pointing the characteristics of the mobile systems covering in the city of Natal (state of Rio Grande do Norte, Brazil). A mobile laboratory was set up, using the infra-structure available and frequently used by ANATEL. The measures were taken in three different areas: one characterized by high buildings, high relief, presence of trees and towers of different highs. These areas covered the city s central zone, a suburban / rural zone and a section of coast surrounded by sand dunes. It is important to highlight that the analysis was made taking into consideration the actual reality of cellular systems with covering ranges by reduced cells, with the intent of causing greater re-use of frequencies and greater capacity of telephone traffic. The predominance of telephone traffic by cell in the city of Natal occurs within a range inferior to 3 (three) km from the Radio-Base Station. The frequency band used was 800 MHz, corresponding to the control channels of the respective sites, which adopt the FSK modulation technique. This Dissertation starts by presenting a general vision of the models used for predicting propagation. Then, there is a description of the methodology used in the measuring, which were done using the same channels of control of the cellular system. The results obtained were compared with many existing prediction models, and some adaptations were developed by using regression techniques trying to obtain the most optimized solutions. Furthermore, according to regulations from the old Brazilian Holding Telebrás, a minimum covering of 90% of a determined previously area, in 90% of the time, must be obeyed when implanting cellular systems. For such value to be reached, considerations and studies involving the specific environment that is being covered are important. The objective of this work is contribute to this aspect

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Mesenchymal stem cells (MSCs) are known as a population of multi-potential cells able to proliferate and differentiate into multiple mesodermal tissues including bone, cartilage, muscle, ligament, tendon, fat and stroma. Several applications of the study of EC can be emphasized the therapeutic techniques such as guided bone regeneration by implantation of EC in the affected site, without the need for bone grafts, using titanium as a vehicle. The process of cryopreservation is essential for the maintenance of cell cultures, since the cell line is frozen, it can be maintained in liquid nitrogen for an indefinite period and then thawed for therapeutic or experimental purposes. The aim of this study was to isolate a population of MSCs derived from the subendothelium of the umbilical vein human (MSCs-SUVH) to assess cytogenetic analysis by the possibility of appearance of chromosomal changes in two different situations: MSCs-SUVH regarding the process of cryopreservation and MSCs-SUVH grown on the surface of titanium. Flow cytometry analysis revealed that, this cell population was positive for the markers CD29, CD73 and CD90, but there was no expression of hematopoietic lineage markers, such as CD14, CD34 and CD45 and demonstrated capacity for osteogenic differentiation. The chromosomes obtained from the primary culture of MSCs-SUVH were analyzed by GTW banding technique, and results are described as guidelines to ISCN 2005. There was not the emergence of clonal chromosomal changes in the MSCs-SUVH in different situations analyzed. However one of the strings presented a balanced paracentric inversion, probably a cytogenetic constitutional alterations, which was present before and after the experimental situations that the MSCs-SUVH was submitted

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Recently, genetically encoded optical indicators have emerged as noninvasive tools of high spatial and temporal resolution utilized to monitor the activity of individual neurons and specific neuronal populations. The increasing number of new optogenetic indicators, together with the absence of comparisons under identical conditions, has generated difficulty in choosing the most appropriate protein, depending on the experimental design. Therefore, the purpose of our study was to compare three recently developed reporter proteins: the calcium indicators GCaMP3 and R-GECO1, and the voltage indicator VSFP butterfly1.2. These probes were expressed in hippocampal neurons in culture, which were subjected to patchclamp recordings and optical imaging. The three groups (each one expressing a protein) exhibited similar values of membrane potential (in mV, GCaMP3: -56 ±8.0, R-GECO1: -57 ±2.5; VSFP: -60 ±3.9, p = 0.86); however, the group of neurons expressing VSFP showed a lower average of input resistance than the other groups (in Mohms, GCaMP3: 161 ±18.3; GECO1-R: 128 ±15.3; VSFP: 94 ±14.0, p = 0.02). Each neuron was submitted to current injections at different frequencies (10 Hz, 5 Hz, 3 Hz, 1.5 Hz, and 0.7 Hz) and their fluorescence responses were recorded in time. In our study, only 26.7% (4/15) of the neurons expressing VSFP showed detectable fluorescence signal in response to action potentials (APs). The average signal-to-noise ratio (SNR) obtained in response to five spikes (at 10 Hz) was small (1.3 ± 0.21), however the rapid kinetics of the VSFP allowed discrimination of APs as individual peaks, with detection of 53% of the evoked APs. Frequencies below 5 Hz and subthreshold signals were undetectable due to high noise. On the other hand, calcium indicators showed the greatest change in fluorescence following the same protocol (five APs at 10 Hz). Among the GCaMP3 expressing neurons, 80% (8/10) exhibited signal, with an average SNR value of 21 ±6.69 (soma), while for the R-GECO1 neurons, 50% (2/4) of the neurons had signal, with a mean SNR value of 52 ±19.7 (soma). For protocols at 10 Hz, 54% of the evoked APs were detected with GCaMP3 and 85% with R-GECO1. APs were detectable in all the analyzed frequencies and fluorescence signals were detected from subthreshold depolarizations as well. Because GCaMP3 is the most likely to yield fluorescence signal and with high SNR, some experiments were performed only with this probe. We demonstrate that GCaMP3 is effective in detecting synaptic inputs (involving Ca2+ influx), with high spatial and temporal resolution. Differences were also observed between the SNR values resulting from evoked APs, compared to spontaneous APs. In recordings of groups of cells, GCaMP3 showed clear discrimination between activated and silent cells, and reveals itself as a potential tool in studies of neuronal synchronization. Thus, our results indicate that the presently available calcium indicators allow detailed studies on neuronal communication, ranging from individual dendritic spines to the investigation of events of synchrony in neuronal networks genetically defined. In contrast, studies employing VSFPs represent a promising technology for monitoring neural activity and, although still to be improved, they may become more appropriate than calcium indicators, since neurons work on a time scale faster than events of calcium may foresee

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A number of evidences show the influence of the growth of injured nerve fibers in Peripheral Nervous System (PNS) as well as potential implant stem cells (SCs) to make it more suitable for nerve regeneration medium. In this perspective, this study aimed to evaluate the plasticity of mesenchymal stem cells from bone marrow of mice in the presence of culture medium conditioned with facial nerve explants (D-10) and fibroblast growth factor-2 (FGF-2). In this perspective, the cells were cultivated only with DMEM (group 1), only with D-10(group 2), only with FGF-2(group 3) or with D-10 and FGF-2(group 4). The growth and morphology were assessed over 72 hours. Quantitative phenotypic analysis was taken from the immunocytochemistry for GFAP, OX-42, MAP-2, β-tubulin III, NeuN and NF-200 on the fourth day of cultivation. Cells cultured with conditioned medium alone or combined with FGF-2 showed distinct morphological features similar apparent at certain times with neurons and glial cells and a significant proliferative activity in groups 2 and 4 throughout the days. Cells cultived only with conditioned medium acquired a glial phenotype. Cells cultured with FGF-2 and conditioned medium expressed GFAP, OX-42, MAP-2, β-tubulin III, NeuN and NF-200. On average, area and perimeter fo the group of cells positive for GFAP and the área of the cells immunostained for OX-42 were higher than those of the group 4. This study enabled the plasticity of mesenchymal cells (MCs) in neuronal and glial nineage and opened prospects for the search with cell therapy and transdifferentiation

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T. gondii is an obligate intracellular protozoan and the main cause of retinochoroiditis in humans. The aim of this study was to evaluate the effect of the antipsychotic drugs haloperidol and clozapine on the course of infection by T. gondii of cultured embryonic retinal cells. Embryo retinas of Gallus gallus domesticus (E12) were used for the preparation of mixed monolayer cultures of retinal cells. Cultures were maintained on plates of 96 and 24 wells by 37°C in DMEM medium supplemented with 5% fetal bovine serum for 2 days. After this period, cultures were simultaneously infected with tachyzoites of T. gondii and treated with the antipsychotics haloperidol and clozapine for 48 hours. Treatment effects were determined by both assessing cell viability with the MTT method and evaluating infection outcomes in slides stained with Giemsa. The treatment with haloperidol and clozapine cells infected with T. gondii resulted in higher viability of these cells, suggesting a possible prevention of neuronal degeneration induced by T. gondii. Additionally, intracellular replication of this protozoan in cells treated with haloperidol and clozapine were significantly reduced, possibly by modulation of the parasite s intracellular calcium concentration

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The cultivation of microalgae biomass in order to produce biodiesel arises as an extremely promising aspect, in that the microalgae culture includes short cycle of reproduction, smaller areas for planting and residual biomass rich in protein content. The present dissertation evaluates the performance and features, through spectrometry in the region of infrared with transformed Fourier (FTIR) and spectrometry in the region of UVvisible (UV-Vis), of the extracted lipid material (LM) using different techniques of cell wall disruption (mechanical agitation at low and at high spin and agitation associated with cavitation). The technique of gas chromatography (GC) brought to light the success of alkaline transesterification in the conversion of oil into methyl monoesters (MME), which was also analyzed by spectroscopic techniques (FTIR, proton magnetic resonance (1H NMR) and carbon (13C NMR). Through thermogravimetric analysis (TGA) were analyzed the lipid material (LM), biodiesel and the microalgae biomass. The method which provided the best results concerning the efficiency in extraction of the LP of Monoraphidium sp. (12,51%) was by mechanical agitation at high spin (14 000 rpm), for 2 hours being the ideal time, as shown by the t test. The spectroscopic techniques (1H NMR, 13C NMR and FTIR) confirmed that the structure of methyl monoesters and the chromatographic data (CG) revealed a high content of saturated fatty acid esters (about 70%) being the major constituent eicosanoic acid (33,7%), which justifies the high thermal stability of microalgae biodiesel. The TGA also ratified the conversion rate (96%) of LM into MME, pointing out the quantitative results compatible with the values obtained through GC (about 98%) and confirmed the efficiency of the extraction methods used, showing that may be a good technique to confirm the extraction of these materials. The content of LM microalgae obtained (12,51%) indicates good potential for using such material as a raw material for biodiesel production, when compared to oil content which can be obtained from traditional oil for this use, since the productivity of microalgae per hectare is much larger and requires an extremely reduced period to renew its cultivation

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The Brazilian coast has a wide variety of complex environments and ecosystems along the coast, about 80% are represented by sandbanks and dunes. The coastal ecosystems were the first to suffer the impacts man and places, as the very fragile ecosystems, are somehow altered. Are few areas of restinga well as natural features, very few protected in conservation units. Only in the last two decades the Brazilian restinga have been studies that are showing their importance for biodiversity of the country, though its economic importance remains largely unknown. In Rio Grande do Norte in the restinga vegetation and dune environments extend for almost the entire coast. The dunes are distinguished in the coastal landscape of the state due to the exuberance of its forms, heights and coating plants. The dune system is of fundamental importance for the maintenance of coastal urban settlements, especially for the city of Natal, acting on the hydrological dynamics of water table and reducing the effect of wind and movement of grains of sand to the interior and thus avoiding the burial City. However, the ecosystem of restinga and dune environments have been weakened and destroyed according to the intense urbanization and the knowledge of the vegetation of restinga installed on the dunes are still scarce. Thus, the objective of this study was to characterize the structure and floristic composition of vegetation established on a dune in the Dunes State Park Christmas and gather information to develop a model of recovery of the dune ecosystem. This dissertation is composed of 2 chapters, the first being: Structure of the vegetation of the dunes Dunes State Park in Natal, RN with the objective of describing the structure and composition of species of tree-shrub vegetation of restinga dunes of the Parque das Dunas and second: Recovery of degraded areas in a sand dune, which aimed to review the terms and concepts used in the theme of recovery and the techniques for recovery of degraded areas with emphasis on sandy environments and poor in nutrients, reporting some experiences within and external to Brazil the country, mainly in the Northeast and dunes positive and negative aspects that should be followed in building a model to be adopted for the recovery of local dunes

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The processes of occupation and evolution of natural environments as a result of a disorderly process of implementing economic practices agrosilvopastoris play today an important role in the degradation process of changing the landscape and natural resources of the semiarid Northeast. The Serra de Santana has natural elements important to the state of Rio Grande do Norte as the source of the Potengi. Therefore, this study aimed to analyze the degree of degradation in the municipality of Cerro Cora - RN. We used satellite images Landsat-5 and census data for the year 2008. The method made use of geotechnology which includes land use, NDVI, rainfall, livestock and erodibility in the evaluation of environmental degradation, as well as satellite images of Landsat TM-5, in the years 1984, 1995 and 2008, letters of NDVI, census data regarding the socioeconomic obtained from IBGE. The results showed that the absolute majority in the municipality of Cerro Cora has a low to medium susceptibility, which together represent 63.92% of the municipality, with a regression of disturbed areas and the areas of agriculture, and a recovery of the areas of Caatinga , coming to occupy currently 92% of the municipal territory. A Geographic Information System is indispensable to environmental monitoring of Cerro Cora / RN